Review of the Genus Prodesmodora Micoletzky, 1923 (Nematoda: Desmodorida: Desmodoridae) Обзор Рода Prodesmodora Micoletzky, 1923 (Nematoda: Desmodorida: Desmodoridae)

ZOOSYSTEMATICA ROSSICA, 23(1): 3–6 25 JUNE 2014

Review of the genus Prodesmodora Micoletzky, 1923 (Nematoda: Desmodorida: Desmodoridae) Обзор рода Prodesmodora Micoletzky, 1923 (Nematoda: Desmodorida: Desmodoridae)

S.YA. TSALOLIKHIN

С.Я. ЦАЛОЛИХИН

S.Ya. Tsalolikhin, Zoological Institute, Russian Academy of Sciences, 1 Universitetskaya Emb., St Petersburg, 199034, Russia, E-mail: [email protected]

Practically all nine species of the genus Prodesmodora are known only from type localiti es except for species P. circulata, cosmopolitism of which is doubtful. Morphometric characteristics of all the species are similar. Differentiation of the species is best performed by rectum length, tail length, cephalic setae length and by amphid position. A key for identification of species is given. Из девяти валидных видов рода Prodesmodora практически все известны только из типовых местонахождений, за исключением вида P. circulata, космополитизм которого сомнителен. Морфометрические характеристики всех видов сходны. Дифференцировка видов наилучшим образом осуществляется по длине ректума, длине хвоста, длине головных щетинок и по положению амфида. Приводится ключ для определения видов. Key words: free-living nematodes, taxonomy, key for species identification Ключевые слова: свободноживущие нематоды, таксономия, Nematoda, Desmodoridae, Prodesmodora, ключ для определения видов

INTRODUCTUON 6.6, c=9.1–9.3, c´=4, spic. 28–30 μm, suppl. 1–2. (Gagarin, 1978). The genus is mainly Position of the genus Prodesmodora in terrestrial, with some species from freshwa- the system of Chromadoria group is de- ter habitats. Type species P. circulatа (Mi- batable. In the opinion of some nematolo- coletzky, 1913). gists (Decraemer & Smol, 2006) this genus In the faunal lists species P. circulatа oc- belongs to the order Desmodorida, family curs most commonly, practically all other Desmodoridae and monotypical subfamily species are known only from type localities, Prodesmodorinae. However, according to cosmopolitism of P. circulata is however a different point of view (Andrássy, 2005), doubtful; other species could have been the genus Prodesmodora belongs to the or- identified as P. circulata because of the simi- der Chromadorida and family Microlaimi- larity of morphometric characteristics of dae. Brief diagnosis of the genus is as fol- the majority of representatives of the genus. lows: Cuticle well annulated, not punctat- No new species can be assigned to the ed. Stoma more or less tubular, armed with genus based upon the individual specimens some very small teeth; cephalic setae four, from the meiobenthos samples from differ- short and fine. Amphidial fovea circular. ent water-bodies of the Earth, even when Oesophagus with bulb. Female gonads two, the specimen available to the researcher ovaries reflexed. Male known in one species is significantly different from other spe- only: L=850–890 μm, a=24–24.8, b=6.5– cies of the genus, as for instance in our case

© 2014 Zoological Institute, Russian Academy of Scienсes 4 S.YA. TSALOLIKHIN. REVIEW OF NEMATODE GENUS PRODESMODORA the only adult female from a spring on the [(n=8): L=880–920 μm, a=26–29, b=6.4– bank of the Nubra River at an altitude of 7.2, c=6.2–7.4, V=42–46%; Italy, rhizo- 3148 m above sea level in Himalayas (India: sphere of aquatic plants (Colomba & Vin- 77.555°Е, 34.758°N). In this nematode rec- ciguerra, 1979)] 7(6). Rectum equal to anal diameter or slightly tum length is nearly two times as large as longer. anal diameter. Long rectum is characteristic 8(9). Cephalic setae 5–6 μm ...... only of P. terricola and P. minuta; however, P. circulatа (Micoletzky, 1913) Micoletzky, 1925 in the former rectum length is 3–4 times [(Syn. Tripyla circulata Micoletzky, 1913; Mi- as large as the anal diameter, whereas in crolaimus fluviatilis Cobb, 1914; M. menzeli the latter body length is much shorter than Hofmaenner, 1914; P. wolgensis Micoletzky, in the Himalayan specimen, no more than 1923). (n=7): L=470–960 μm, a=20–30.5, – – – 363 μm. In the other species rectum is either b=6.4 7.8, c=6.4 7.5, V=39 47% (Mico- shorter than or is no more than 1.5 times as letzky, 1925).Cosmopolitan (?), bottom of fresh water-bodies, rhizosphere of aquatic large as the anal diameter. Such a character plants (Andrassy, 2005)] allows placing the above specimen in a new 9(8). Cephalic setae 2–4 μm. species, however, one specimen is not suffi- 10(11). с´ no more than 5.4 ...... cient for this purpose...... P. nigra Ocaña et al., 2001 It would be more correct to regard the [(n=4): L=530–540 μm, a=24–28, b=6.3– earlier mentioned species (Tsalolikhin et 6.7, c=6.8–7.4, V=45–49%; Spain, soil (Oc- ñ al., 2012) Prodesmodora sp. (larva) from a a & al, 2001)] ´ the sample of the sand beach of the Bor- 11(10). с no less than 5.5 ...... P. nurta Zullini, 1988 neo Island (Malaysia) as a representative [(n=6): L=490–590 μm, a=22–24, b=6–6.6, of the family Microlaimidae gen. sp. (Cinc- c=5.9–6.6, V=43–46%; Ethiopia, Lake Zwai tonema ?). (bottom) (Zullini, 1988)] 12(1). Body length no larger than 420 μm. Key to species of the genus Prodesmodora 13(14). Rectum nearly 2 times as large as anal di- Micoletzky, 1923 ameter ...... P. minuta Schneider, 1937 [(n=2): L=332–363 μm, a=19–20, b=5.6– 1(12). Body length no less than 480 μm. 6.2, c=6.7–7.6, V=46–47%; Java Island, hu- 2(5). Rectum no less than 1.5 times as large as mid mosses (Schneider, 1937)] anal diameter. 14(13). Rectum no more than 1.5 times as large 3(4). Rectum 3–4 times as large as anal diameter as anal diameter, equal to it or slightly small- ...... P. terricola Altherr, 1952 er than anal diameter. [(n=8): L=490–730 μm, a=21–28, b=4.8– 15(16). Amphid slightly ellipsoid ...... 6.5, c=5.8–8, V=48–57% (Altherr, 1952)...... P. loksai Andrássy, 1989 Europe humid soil (Altherr, 1952; Andrassy, [L=370 μm, a=25, b=5.8, c=6.2, V=46% (An- 2005)] drássy, 1991). Ecuador, humid mosses; Hun- 4(3). Rectum nearly 2 times as large as anal di- gary, humid soil (Andrássy, 1989; 2005)] ameter ...... Prodesmodora sp. 16(15). Amphid rounded. [L=857 μm, a=26.8, b=7.2, c=5.7, c´=8.8, 17(18). Length of cephalic setae no more than

V=42%. Rectum 31 μm, Q1=146 μm (egg 1/3 of head width ...... ñ 57 × 23 μm), Q2=126 μm (egg 58 × 23 μm)...... P. zullinii Oca a et al., 2001 Head 19 μm, cephalic setae about 3 μm, very [(n=23): L=340–360 μm, a=20–32, b=5.3– thin, amphid situated at a distance of 18 μm 5.5, c=6.2–6.8, V=49–51%; Spain, soil (Oc- from the anterior end of the body, amphid aña & al., 2001)] diameter about 4 μm. NR=57%. Himalayas, 18(17). Length of cephalic setae no less than 1/2 spring near Nubra River: 77. 555°E, 34.758°N of head width ...... (Figs 1–4)] . . . P. arctica (Mulvey, 1969) Andrássy, 1984 5(2). Rectum shorter than anal diameter, equal [(Syn. Microlaimus arcticus, Mulvey, 1969). to it, or slightly longer. (n=8): L=320–400 μm, a=20–32, b=5–7, 6(7). Rectum shorter than anal diameter . . . . . c=6.7–8.2, V=48–55%; Canada, humid soil P. pantalicae Colomba et Vinciguerra, 1979 (Mulvey, 1969)]

Figs 1–4. Prodesmodora sp.: 1, entire body of female; 2, head; 3, oesophagus; 4, tail.

ACKNOWLEDGMENTS Untersuchung des schweizerischen National- parks, 3(26): 315–356. I wish to thank my colleagues L. Borkin and Andrássy I. 1989. Six new nematode species S. Litvinchuk for collecting the nematodes in from South America. Acta zoological Hun- Himalayas. garica, 35(1–2): 1–16. Andrássy I. 1991. The free-living nematode REFERENCES fauna of the Batorligen nature reserves. In: Altherr E. 1952. Les nématodes du Parc Na- Mahunka S. (Ed.) The Batorliget Nature Re- tional Suisse. Ergebnisse wissenschaftlichen serves. Budapest: 129–197.

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